Conductive Aramid Fibers from Electroless Silver Plating of Crosslinked HPAMAM-Modified PPTA: Preparation and Properties.

Conductive aramid (PPTA) fibers are highly needed for making flexible conductive materials, antistatic materials, and electromagnetic shielding materials. In this work, silver-plated conductive PPTA fibers with high conductivity and excellent mechanical properties were prepared by the electroless plating of PPTA fibers modified with crosslinked hyperbranched polyamide-amine (HPAMAM). The crosslinked HPAMAM creates a stable interface between the PPTA fibers and the silver plating. The morphology and physicochemical properties of the modified and the silver-plated fibers were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, atomic force microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and thermogravimetric analysis. Three epoxy crosslinking agents with different chain lengths were used to crosslink HPAMAM, and the effects of HPAMAM concentration, crosslinking agent dosage, and crosslinking time on the resistance of the fibers were studied. The long chain crosslinking agent appears to be beneficial to silver plating. The lowest resistance (0.067 Ω/cm) was attained when HPAMAM was modified by diethylene glycol diglycidyl ether (1:1 molar ratio), and 20 g/L HPAMAM was used to modify the PPTA fibers. The tensile strength of the original PPTA fibers decreased by only 3% or less after silver plating.